In existing optical communication technologies, reliable information transmission with high speed and long hours is conducted by using optical signals as carriers of information. The coupling effect of optical components and transmission paths (optical fibers) in an optical module as a core component in the field of optical communications, greatly affects the strength and quality of the optical signals, and thus becomes one of the key factors affecting the information transmission.
Currently, the method of achieving the optical path coupling of the optical components and transmission fibers in the optical module includes active coupling and passive coupling.
The process of the active coupling method includes: fixing a laser which serves as a light source on a PCB, then controlling the laser to emit light, adjusting, by using a coupler, the spatial position of an optical lens module which is used as a device for changing the optical transmission path, and detecting the light intensity which is coupled to the optical fiber by this module, and when the light intensity output by the optical fiber reaches a maximum, determining the position of the lens at this time as the optimal coupling position.
The process of the passive coupling method includes: first fixing the laser, and then acquiring images of the laser and the optical lens module respectively by using two cameras, transferring the images to a PC, adjusting the position of the lens, and when centers of the two images overlap, determining the position of the lens at this time as the optimal coupling position.
A special coupler needs to be used if the active coupling method is adopted, and two cameras need to be used if the passive coupling method is adopted, which result in that prices of the devices used for coupling are relatively high, and the working processes are complicated. Moreover, the UV glue needs to be used for fixing after the optimal coupling position is found for both the active coupling method and the passive coupling method. The UV glue is cured fast by ultraviolet ray irradiation; as its strength is relatively low, the glue then is used to perform high temperature curing. Because the laser, the optical lens module and the optical fiber, which constitute the optical path, are not mechanically fixed with high strength with respect to each other, it is very possible that the optical lens module deviates from the coupling position during the manual operations before the black glue curing, thereby resulting in a poor coupling effect of the optical path.